Search results for "Rana temporaria"

Kāda līdz šim nepazīta cikliska amfībiju dzimumpazīme: vardes priekškāju skeleta sezonu variācijas

1924

Atsevišķs iespiedums no: Latvijas Universitātes Raksti, XI. 1924. Kopsavilkums franču valodā.

Excretion and metabolism of phenol, 4-nitrophenol and 2-methylphenol by the frogs Rana temporaria and Xenopus laevis.

1987

1. Rana and Xenopus excrete 90-95% dose, and metabolize 50-65% dose of phenol, 4-nitrophenol and 2-methylphenol within 24 h, to about the same extent. 2. Kinetic data for the excretion of phenols from both species fit a two-compartment model. The elimination constants of Rana and Xenopus are not significantly different. 3. Metabolism is mostly conjugation by glucuronidation and sulphation of the original phenols. Additionally, oxidations leading to dihydroxyphenols and benzoic acid from 2-methylphenol, and reduction of 4-nitrophenol occur, followed by conjugation. 4. There is an important difference between the metabolite patterns of Rana and Xenopus in that the latter is unable to glucuron…

6-Phosphofructokinase from frog skeletal muscle: purification and properties

1990

Exercise and recovery in frog muscle: metabolism of PCr, adenine nucleotides, and related compounds

1996

The effects of exercise (swimming), fatigue, and recovery on the intracellular pH (pHi), energy-rich phosphates, and related metabolites were studied in the gastrocnemius muscle of common frogs (Rana temporaria) at 20 degrees C. Exercise caused a rapid decrease in the content of phosphocreatine (PCr) and a corresponding increase in that of Pi. The ATP level remained virtually constant for 1 min; its precipitous decrease during the following minute was associated with a rise in the contents of inosine 5'-monophosphate (IMP) and NH4+, indicating a marked activation of AMP deaminase. Five minutes of swimming caused severe fatigue, which was correlated with decreases in muscle PCr (-85%), ATP …

Control of glycolysis in vertebrate skeletal muscle during exercise

1996

The gastrocnemius muscle of the frog (Rana temporaria) has a high capacity for anaerobic glycolysis from glycogen. Glycolytic metabolites and effectors of phosphofructokinase, particularly the hexose bisphosphates, were followed in muscle during exercise (swimming between 5 s and 5 min), recovery (rest for up to 2 h after 5 min of swimming), and repeated exercise (swimming for up to 60 s after 2 h of recovery). Glycogen phosphorylase and phosphofructokinase were swiftly activated with exercise. The hexose bisphosphates followed markedly different time courses. Fructose 1,6-bisphosphate was transiently increased in both exercise and repeated exercise. This appears to be an effect rather tha…

Some pharmacological properties of the false cholinergic transmitter acetylpyrrolidinecholine and its precursor pyrrolidinecholine

1976

The acetylchline analogue acetylpyrrolidinecholine as well as the choline analogue pyrrolidinecholine were synthesized and the cholinergic properties of both substances were investigated on the guinea-pig ileum, rat blood pressure and frog rectus abdominis muscle. Acetylpyrrolidinecholine was 3-5 times less potent than acetylcholine on the three preparations tested. The dose-response curves to acetylpyrrolidinecholine were shifted to the right in a parallel manner by atropine and (+)-tubocurarine. The dissociation constants for atropine and (+)-tubocurarine obtained with acetylpyrrolidinecholine as agonist were not different from those obtained with acetylcholine. This indicates that acetyl…

Metabolism of 3-nitrophenol by the frog Rana temporaria.

1986

1. Frogs injected with 3-nitrophenol excreted 85–93% of the administered dose within 17h; 70–90% dose was metabolized.2. Metabolites identified comprise 3-nitrophenyl glucuronide (57% dose), 3-nitro-phenyl sulphate (24% dose), and 3-acetamidophenyl sulphate (2% dose). Traces of the following metabolites were found: 3-acetamidophenyl glucuronide, 3-acetamidophenol, 4-nitrocatechol, nitroquinol, 4-nitrocatechol sulphate and nitroquinol sulphate.

Hydroxylation and conjugation of phenol by the frog Rana temporaria.

1985

1. Frogs injected with phenol excrete 67–95% of dose in 15h; 32–87% of dose are metabolites.2. Metabolites identified were phenyl sulphate (15–44% of dose), phenyl glucuronide (10–25% of dose), catechol sulphate (up to 7% of dose), quinol sulphate (1–25% of dose), resorcinol and catechol (traces).

Elimination and distribution of different substituted phenols by frog (Rana temporaria) and crayfish (Astacus leptodactylus)

1981

Humic acid reduces gonadotropin activity and hormonal sensitivity of frog oocytes

2005

The specific stimulatory effect of sturgeon Acipenser güldenstädti Br. gonadotropic hormone (GTH) on frog Rana temporaria L. oocyte maturation in vitro was investigated in relation to humic acid (HA) concentrations from 12.5 to 50 mg/l. HA was observed to bind to both the follicular membrane of the oocytes and the GTH molecule, reducing the oocytes' hormone sensitivity and maturation ability. It was also shown that HA inactivated GTH, lowering its specific ability to stimulate oocyte maturation.